Aim:In Senegal, uncontrolled cross-breeding of cattle breeds and changes in production systems are assumed to lead to an increase of gene flow between populations. This might constitute a relevant threat to livestock improvement. Therewith, this study was carried out to assess the current genetic diversity and the phylogenetic relationships of the four native Senegalese cattle breeds (Gobra zebu, Maure zebu, Djakoré, and N’Dama).Methods:Genomic DNA was isolated from blood samples of 120 unrelated animals collected from three agro-ecological areas of Senegal according to their phenotypic traits. Genotyping was done using 11 specific highly polymorphic microsatellite makers recommended by Food and Agriculture Organization. The basic measures of genetic variation and phylogenetic trees were computed using bioinformatics’ software.Results:A total of 115 alleles were identified with a number of alleles (Na) at one locus ranging from 6 to 16. All loci were polymorphic with a mean polymorphic information content of 0.76. The mean allelic richness (Rs) lay within the narrow range of 5.14 in N’Dama taurine to 6.10 in Gobra zebu. While, the expected heterozygosity (HE) per breed was high in general with an overall mean of 0.76±0.04. Generally, the heterozygote deficiency (FIS) of 0.073±0.026 was relatively due to inbreeding among these cattle breeds or the occurrence of population substructure. The high values of allelic and gene diversity showed that Senegalese native cattle breeds represented an important reservoir of genetic variation. The genetic distances and clustering trees concluded that the N’Dama cattle were most distinct among the investigated cattle populations. So, the principal component analyses showed qualitatively that there was an intensive genetic admixture between the Gobra zebu and Maure zebu breeds.Conclusions:The broad genetic diversity in Senegalese cattle breeds will allow for greater opportunities for improvement of productivity and adaptation relative to global changes. For the development of sustainable breeding and crossbreeding programs of Senegalese local breeds, effective management is needed towards genetic selection and transhumance to ensure their long-term survival.

Seasonality and range of fruit fly (Diptera: Tephritidae) host plants in orchards in Niayes and the Thiès Plateau (Senegal).Abstract -Introduction. Senegal produces up to 150,000 t of fruit, of which 60,000 t are mangoes. Fruit production is important for the Niayes region, where 60% of total production is of mangoes, with citrus production coming next at 24%. Mango losses have become more substantial since the arrival of Bactrocera invadens in Senegal. The pest population increases in the mango ripening period, but little is known about its secondary hosts. Materials and methods. Fruits of cultivated and wild plants were collected regularly from April to December 2008 inside and around 19 orchards in eleven localities in the Niayes and Thiès areas in Senegal. The samples were monitored to identify any fruit flies present so that a list of host plants could be compiled. For mango, the study focused on establishing the influence of certain parameters such as the variety, the fruit size, the color, the flowering pattern and the physiological levels of infestation due to B. invadens and Ceratitis cosyra. Orchards were classified either as traditional (many mango varieties and many fruit species grown together in a stand) or intensive (fields of monovarietal mango trees), according to their composition and how they were managed. Results and discussion. A total of 663.2 kg of fruit, including those of 24 mango varieties, 13 citrus species with five lime varieties, two orange varieties and four pomelo varieties along with other cultivated and wild plants, were sampled both as fallen fruit and from the trees. Traditional orchards were more infested than the modern ones. B. invadens was significantly dominant over the other flies emerging such as C. cosyra, C. capitata, C. punctata, C. bremii, Bactrocera cucurbitae, Capparimyia bipustulata, Carpomyia sp. and Dacus sp. B. invadens was found on the 24 varieties of Mangifera indica, the 13 citrus species, and the other cultivated plants and wild plants sampled. Some host plants supported a relatively high level of fruit flies before the mango ripening period. Mangifera indica was infested principally by B. invadens and C. cosyra. C. cosyra was significantly present on the first fruit trees to flower, mostly in early varieties, while B. invadens infested all the varieties whatever the fruit development stage, the color, or the flowering pattern. Conclusion. Because of the host plants' diversity and varieties the traditional orchards were more infested than the modern ones. The management of this pest needs an Integrated Pest Management system based on a back-to-basics study of the infesting fruit flies, existing parasitoids and their hosts.Senegal / fruit crops / host plants / Mangifera indica / Citrus / Tephritidae / Bactrocera invadens / Ceratitis cosyra / orchards / sampling Saisonnalité et gamme des mouches des fruits (Tephritidae, diptères) identifiées dans les plantes hôtes des vergers des Niayes et du plateau de Thiès (Sénégal).Résumé -Introduction. La production fru...

NiO is one of the most important candidates for semiconductors metal oxide nanocrystals by the arrangement of photocatalytic application. However, the photocatalytic performance of biosynthesized nanocrystals using Aspalathus linearis (Burm.f.) R. Dahlgren has not been investigated yet. In this contribution, we synthesize α-Ni(OH) 2 using an A. linearis. A heat treatment of the α-Ni(OH) 2 is carried out at 300-400°C for 2 h at normal air yields. Furthermore, we have characterized the structural, optical and photocatalytic activity of the samples. The optical results indicate that biosynthesized nanocrystals exhibit UV-visible light absorption and a narrow range distribution of intense green light (518.95 nm) emission, which decreases significantly as annealing temperature increases. The bandgap energies of the sample annealed at 300-400°C shift to lower photon energy, compared to bulk NiO (∼ 4 eV). Moreover, the photocatalytic experimental results reveal that NiO nanocrystals enable color switching of methylene blue.

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The foraging pattern of four sympatric fungusgrowing termite species was followed for five months of the dry season in a semi-arid savanna (Senegal). Experimental plots were established with and without termites (exclusion with insecticide) and amended with different litter quality: Acacia leaves, millet canes, ground millet (<500 µm), Combretum wood and cattle manure. Results showed different foraging patterns between the fungus-growing species. Odontotermes nilensis, for example, rapidly developed its foraging activity on the litter. In contrast, Macrotermes subhyalinus delayed its foraging activity but, extensively collected the food after its discovery. Differences in food preference were evident between the termite species: Odontotermes nilensis foraged preferentially on millet, canes and Acacia leaves, Macrotermes subhyalinus preferred cane and ground millet. Ancistrotermes guineensis selected the millet, and Microtermes sp. was mostly recorded foraging on pieces of dead wood. Relationships between different foraging parameters were established to assess the relative intensity of this activity over the dry season. The comparison between untreated plots and plots treated with Fipronil® (Aventis) clearly demonstrated that the exclusion of termites from part of the savanna is possible and that this possibility can be used to study their role on the soil and organic matter cycle in situ.

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Fruit phenology of citruses, mangoes and papayas influences egg-laying preferences of Bactrocera invadens (Diptera: Tephritidae) Abstract-Introduction. African fruit production, as well as regional and international fruit trade, have experienced heavy economic losses over the past decade due to the damage caused by fruit flies, especially B. invadens Drew Tsuruta & White (Tephritidae: Diptera). Bactrocera invadens attacks fruits belonging to numerous botanical families, several of which are of great economic importance. The females of these flies generally lay their eggs in mature fruits, but some can lay in green-immature fruits. Materials and methods. The influence of the species, variety and phenology of fruits on the fruit attractiveness to B. invadens and the elicitation of B. invadens egglaying behaviour were studied in the laboratory. Fruits harvested regularly during the years 2008 and 2009 from orchards in the Niayes area (Senegal) were exposed to gravid females in cages set for the different factors tested. The exposed fruits were then incubated and the pupae emerging from them were counted. Results and discussion. Bactrocera invadens females laid eggs in ripe fruits. Within the same fruit species, the variety plays an important role in egg-laying preference. Hence, among the mango varieties tested, the Pêche variety hosted the highest number of pupae per fruit, while the Palmer variety hosted the lowest number. Comparison among different fruit species showed that mature papaya was more infested than mature mango or citrus. Furthermore, flies were unable to develop on lime. Conclusion. Our study showed that B. invadens can infest green and ripe host fruits, and even immature abscised fruits. Consequently, management of this pest must include preventive measures in the development and implementation of an integrated management system. Senegal / Mangifera indica / Carica papaya / Citrus / fruits / phenology / maturity / Tephritidae / Bactrocera invadens / oviposition La phénologie des fruits d'agrumes, mangues et papayes influence les préférences de ponte de Bactrocera invadens (Diptera : Tephritidae). Résumé-Introduction. La production fruitière ainsi que le commerce régional et international des fruits enregistrent de lourdes pertes économiques ces dix dernières années en Afrique, imputables aux dégâts causés par les mouches des fruits, notamment par B. invadens (Tephritidae : Diptera). Bactrocera invadens s'attaque à des fruits appartenant à de nombreuses familles botaniques dont plusieurs ont une grande importance économique. Les femelles de ces mouches pondent généralement dans les fruits matures mais certaines peuvent pondre dans les fruits immatures. Matériel et méthodes. L'influence de l'espèce fruitière, de la variété de fruit, et de la phénologie des fruits sur l'attractivité de B. invadens et la stimulation de son comportement d'oviposition ont été étudiées au laboratoire. Des fruits récoltés régulièrement au cours des années 2008 et 2009 en vergers de la zone des Niayes (Sénégal) ont été expos...

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